Closure for access opening in propeller spinner



21, 1956 L. AVONDOGLIO 2,759,624

CLOSURE FOR ACCESS OPENING IN PROPELLER SPINNER Filed June 19, '1952 2Sheets-Sheet 1 4 6 30 44/ F K31 J6 E 5? INVENTOR LEO AVONDOGLIO Aug. 2l,1956 1 L. AVONDOGLIO 2,759,624

CLOSURE FOR ACCESS OPENING IN PROPELLER SPINNER Filed June 19, 1952 2Sheets-Sheet 2 lNVENTOR LE0 AVONDQGLIQ ATEORNEY United States PatentCLOSURE FOR ACCESS OPENING IN PROPELLER SPINNER Leo Avondoglio, Verona,N. J., assignor to Curtiss-Wright Corporation, a corporation of DelawareApplication June 19, 1952, Serial No. 294,341

2 Claims. (Cl. 220-35) This invention relates to spinners for aircraftpropellers and provides, on the one hand, a construction for a quicklydetachable spinner and, on the other hand, a flush access door for arotating or a non-rotating body.

In the design and construction of spinners for the propellers ofaircraft a requirement is to make the spinner unit by the attachment ordetachment respectively, of a small number of securing bolts all locatedin the same plane and all readily accessible from the exterior of thespinner. Access openings are provided in the spinner so that the boltsmay be reached, and I further provide closures for these access openingswhich normally provide a flush outer surface for the spinner and yet,which are readily movable to uncover the access openings.

Objects of the invention are to provide a quickly detachable spinner andto provide a simple closure for an access opening which is particularlysuitable for a rotating body. A further object is to provide a closurefor an access opening, which if left open inadvertently, willautomatically close upon rotation of the body.

Further objects of the invention will become apparent in reading theannexed detailed description in connection with the drawings, in whichsimilar reference characters denote similar parts and in which:

Fig. 1 is a longitudinal elevation, partly broken away, of a propellerand spinner assembly according to the invention.

Fig. 2 is a front elevation of the propeller and spinner assembly.

Fig. 3 is a fragmentary plan view of an access opening and a closuretherefor.

Fig. 4 is an end elevation of the access opening and closure.

Fig. 5 is a section on the line 5--5 of Fig. 4.

Referring first to Figs. 1 and 2, I show a propeller hub of any suitabletype from which blade sockets 12 extend, and in which sockets blades 14are secured. The hub 10 is mounted in a conventional manner, not shown,on a driving shaft. The structure upon which the propeller is mountedincludes a rearward stationary streamlined cowling 16. Mounted upon thepropeller is a spinner 18 which, as shown, embraces the propeller huband provides a streamlined nose for the stationary cowling 16 and blendswith the streamline of the stationary cowling at a spinner rearward edge20. Since the spinner rotates with the propeller there is a gap 22between the rear edge of the rotating spinner and the stationary cowling16.

The spinner 18 is mounted upon two annular bulkheads 24 and 26 which aresecured at 28 and 30 respectively to structural portions of thepropeller hub. The forward bulkhead 24 comprises, at its outer edge, aresilient annular wear strip 32. The spinner includes an inwardlyextending annular flange 34 and a substantial cylindrical annular member36 secured thereto, the member 36, upon assembly of the spinner over thepropeller hub, engaging the wear strip 32 so that the forward portion ofthe spinner is securely piloted upon the bulkhead 24.

The rearward portion of the removable spinner arrangement comprises aninwardly turned annular flange 38 which abuts an outer portion of thebulkhead 26. The flange 38 carries a plurality of bolts 40 securedthereto which bolts pass through appropriate holes in the outer portionof the bulkhead 26 so that nuts 42 may be spun on the bolts to securethe flange 38 to the bulkhead 26.

The outer rim of the bulkhead 26 is provided with rearwardly turnedskirt portion 44 which forms a streamlined prolongation of the surfaceof the spinner 18 and which blends the spinner as mentioned previously,with the streamline of the stationary cowling 16. A plurality of accessopenings 46 are formed in the skirt 44 so that a mechanic may insert awrench through the access openings to tighten or loosen the nuts 42. Ifthe nuts 42 are removed, the entire spinner assembly including the parts38, 36, 34, and 18 may be slid forwardly and removed from the propeller.After removal of the spinner, the propeller assembly may be serviced orremoved in the conventional manner. Where the terms forward or rearwardare used herein, they refer to a tractor propeller assembly. If theassembly is a pusher, forward means outboard and rearward means inboard.

A further feature of the spinner consists in providing slots 50 andopenings 52 extending from a central location toward the rear of thespinner 13 to accommodate the projecting propeller blades 14. An insert52 which blends with the surface of the spinner 18 is secured to thebulkhead 26 to complete the spinner form behind each propeller blade.Without the inserts 52, there would be gaps behind the propeller bladeson account of the slots 50 which are necessary for assembly anddisassembly of the spinner. Within the spinner and bordering each slot50, a reinforcing channel member 56 is secured, this channel memberserving to prevent bulging of the unsupported spinner portions when thespinner is rotating.

The access openings 46 unless closed in some manner, would leave adiscontinuity in the streamlined spinner surface. To close theseopenings, I provide access doors which are shown in Figs. 35. Eachaccess door consists of a closure plate 60 which is exteriorly formed tolie flush with the spinner skirt 44, the plate 60 being appropriatelycurved to conform to the curvature of the spinner. The plate 60 issecured to a supporting member 62 which comprises a bridge portion 64underlying and secured to the plate 60 and underlying part of the skirt44, inbent end portions 66 by which the member 62 is supported, and ashelf portion 68 which serves as a position limit stop for the closureassembly when in the open position. The portions 66 are provided withpivot openings 70 which are journalled on bolts 72 mounted in brackets74 secured as by bolts or rivets 76 to the bulkhead 26. By thisarrangement, the member 62 with the closure plate 60 may be swung asshown in Fig. 5 between a closing position (full lines) and an openingposition (dotted lines). When in the closed position, the plate 60 isflush with the spinner surface. When in the open position, the plate 60lies within the cowling and the portion 68 of the member 62 provides ashelf within the spinner. Opening of the member 62 is accomplishedmerely by pressing the fingers upon the rearward edge of the plate 60and swinging it about the pivots 72 whereupon access may be had to thespinner holding nut 42. To provide small clearance for the plate 60 inthe opening 46, the rearward edge of the latter is bevelled as shown.The shelf 68 provides a convenient means to catch the nut 42 after it isremoved from its bolt to prevent its dropping into the large spinnerhollow. When the spinner is assembled, the nuts 4-2 are applied throughthe access openings 46. The closures 60, 62 may be moved into theclosing position by hand, by manipulation through the access openings,or they may be left open. If they are left open, they will be flung to aclosed position upon rapid rotation of the spinner since centrifugalforce urges them to the closed position on account of the off-setlocation of the center of gravity of the closure with respect to thepivots 72.

Means are provided to hold the closure elastically in either the open orclosed positions. This means comprises tension springs 78, each havingan end hooked to the portion 66 of a member 62, and an end to a tab 80formed integrally with each bracket 74. The springs 78 are so locatedthat their ends are off-set from the pivot axis '72 whereby the springpasses over the axis as a center to hold the closure either open orclosed as clearly shown in Fig. 5. The springs 78 need not be stiff;their sole function is to hold the closure 62 open or closed duringassembly or disassembly operations. During rotation of the spinner, theclosures are held in flush position by the action of centrifugal forcethereon as previously described.

Though one embodiment of the invention is shown, it is to be understoodthat the invention may be applied in various forms and in variousenvironments. Changes may be made in the arrangements shown withoutdeparting from the spirit of the invention. Reference should be had tothe appended claims for definition of the limits of the invention.

What is claimed is:

1. In a body including a wall having an access opening therein andincluding a portion extending inwardly from the wall adjacent the edgeof the opening, brackets within the body wall and secured to the body, aclosure member for the access opening having inwardly disposed tabscooperating with said brackets, pivot means between and engaging saidtabs and brackets, said closure member being swingable on said pivotmeans to close the access opening in substantially flush relation tosaid wall, and to move inwardly and uncover the access opening whereuponsaid closure member lies inwardly of said wall and substantially normalthereto, and a shelf member secured to said closure member substantiallynormal thereto along an edge thereof remote from said extending portion,said shelf member being movable with said closure member so that whensaid closure member is flush with said wall, the shelf member projectssubstantially normally and inwardly from said wall, and so that whensaid closure member uncovers the access opening, said shelf engages saidbody extending portion and forms therewith and with said closure membera pocket within said body.

2. Structure according to claim 1 including an overcenter spring meansacting between said bracket and said closure member to hold said closuremember in covering or uncovering position relative to the accessopening.

References Cited in the file of this patent UNITED STATES PATENTS1,533,682 Woywot Apr. 14, 1925 1,799,897 Gronbech Apr. 7, 1931 1,984,931Koplin et al Dec. 18, 1934 2,078,033 Klein Apr. 20, 1937 2,140,621Gerlach Dec. 20, 1938 2,159,477 Friedman May 23, 1939 2,303,578 PorterDec. 1, 1942 2,336,256 lunger Dec. 7, 1943 2,520,687 Martin et a1 Aug.29, 1950 2,597,014 Mariani May 20, 1952 FOREIGN PATENTS 254,872 GreatBritain July 15, 1926

